Information management system supporting multiple electronic tags

ABSTRACT

A system for identifying multiple electronic tags, the system including a plurality of electronic tags attachable to a single object, each electronic tag having a non-overlapping readable region, and each electronic tag having a unique identifier, an electronic tag reader configured to read the unique identifier of each electronic tag within the non-overlapping readable region, selective shielding of each electronic tag, and a computing system connected to the electronic tag reader to provide digital services in response to reading the unique identifier of each electronic tag.

FIELD OF THE INVENTION

The present invention relates to a system for transferring electronicinformation using multiple electronic tags. More particularly, thepresent invention relates to object attachable radiofrequency electronictags and tag readers connected to a computer network.

BACKGROUND AND SUMMARY OF THE INVENTION

Tagging items with barcodes or symbols that facilitate optical characterrecognition has long been used to identify and track productinventories, baggage, paper checks, or other movable items susceptibleto misplacement or loss. Unfortunately, such optically perceptible tagsmust remain visible for identification, and can be easily renderedunreadable by surface marks or other damage.

To improve tracking reliability, attempts have been made to useradiofrequency based electronic tags. Such tags typically have asemiconductor memory for data storage, processing logic, and a smallantenna for broadcasting data, all embedded in rugged epoxy,thermoplastic, or other suitable plastic containers. Data storagecapacity typically ranges from a few bits to many kilobits, with 64 bitsbeing typical. Tags can include read only memory (ROM), electricallyprogrammable or erasable (EPROM and EEPROM), or even flash memory. Anelectronic tag can be powered by a long lasting small battery,photovoltaic power, thermal convertor, inductive power converter thatrelies on externally applied electromagnetic energy, or any othersuitable power supply.

Unfortunately, since such electronic tags broadcast information whenpowered, use of large numbers of electronic tags in close physicalproximity is difficult. For example, if multiple electronic tags aresituated within a few centimeters of each other, their overlapping databroadcasts could interfere with each other, making it difficult todetermine tag identity. Such problems have generally limited electronictag placement by requiring only one tag per object, with each objectbeing well separated from each other during data transfer. Thisrequirement has limited use of electronic tags in an office environment,where large numbers of tags could be profitably used for trackingpapers, files, or other printed material.

In the modem office environment, the management of paper documents isnot well coordinated with the management of their electroniccounterparts. If an electronic tag is attached to a physical document, auser can access some associated virtual representation (e.g. an ASCIItext file) by placing it near an augmented computer equipped with a tagreader. The resulting system is a powerful tool for maintaining a bridgebetween physical and virtual representations of documents, or, ingeneral, for augmenting physical objects with virtual associations.Advantageously, the present system can be used to track multiple taggeddocuments in close proximity, or to allow performance of variousselected services (e.g. printing, e-mailing, discarding electroniccopies, opening electronic applications)

The present invention meets these requirements by providing a system foridentifying multiple electronic tags that includes a plurality ofelectronic tags attachable to a single object, each electronic taghaving a non-overlapping readable region, and each electronic tag havinga unique identifier. One or more electronic tag readers are configuredto read the unique identifier of each electronic tag within thenon-overlapping readable region, and a computing system is connected tothe electronic tag reader to provide digital services in response toreading the unique identifier of each electronic tag. In certainembodiments, the electronic tags can have integral sensor systems thatdetect, for example, light, location, acceleration, or other physicalproperties, allowing provision of particular digital services related tothe sensed properties.

Such a system is particularly useful for multiple tagging ofsubstantially three-dimensional objects (solids) or two-dimensionalobjects (sheets) with large numbers of distinct electronic tags. Forexample, a multifaced solid such as a polygon can have each face, edge,or vertex equipped with a unique electronic tag that invokes a digitalservice (or provides parameters for enabled digital services). Varioussymbolic indicia such as text, graphics (pictures or line drawings),color codings, texture codings, etc. can be used to assist a user inassociating a particular tag with a digital service.

The foregoing electronic tags can be read by tag readers attached todesktop computers, or in certain embodiments, by tag readers integral orclosely attached to portable or hand holdable computers. Such portablecomputers can also support wireless network transceivers forcommunication with a computer network, extending the range of supporteddigital services.

In operation, at least one electronic identification tag is affixed toeach physical item that is associated with digital services. These tagscan be small radio frequency transponders comprised of an integratedcircuit, containing a unique user accessible 39-bit identificationnumber. A small coil inductively powers the tag, and an antenna is usedto broadcast the identification number. In certain embodiments, theantenna can be separate from the coil, or alternatively, a dual-useinductive power coil/antenna coil can be used.

A tag reader that includes transmitter and receiver components isaffixed to a computational device such as a hand held computer. The tagreader transmits a pulse that momentarily energizes the tag through itscoil until it has sufficient power for transient transmission of itsidentification number. The communication between tag and tag reader onlyoccurs when both are proximate, with an actual distance varying based onsize of the antenna attached to the tag and to the transmitter, from adistance of a few inches to that of several feet. Once theidentification number (transmitted serially) is received, the tag readerpasses this on to the computer system as an ASCII string, via a serialRS-232 output or some other suitable connection, while simultaneouslyproviding user feedback to confirm reading of the tag. User feedback canbe visual (e.g. blinking or turning on an LED status light, text basedor iconic display presentations), auditory (e.g. an audible buzz orbeep), tactile (e.g. a button being raised or a perceptible structurerotation), or combinations of the foregoing.

Upon receipt of the identification number, a computer based applicationprogram interprets the identification input string, determines thecurrent application context, and provides appropriate digital services.For example, an ASCII database that maps identification numbers to oneor more digital services can be used. One common action is a (program,identification number) pair that invokes the identified program on theassociated identification number. If the received identification numberhas not been previously registered, i.e. associated with an action inthe ASCII database, the user can be prompted to enter an action(s) andany associated parameters via a dialog box. Network and serverconnectivity is provided by a separate wireless radiofrequency orinfrared networking system. If the program or the file to be retrievedreside on the network, filenames that are independent of the particularsensing computer can be used.

In addition to an identification number, certain embodiments of tags inaccordance with the present invention can convey small amounts ofmodifiable data (maintained, e.g., in flash memory). For example, dataprovided by sensors embedded or attached to the tag can be used todetect folding, twisting, or bending of the tagged object.Alternatively, a number of accelerometers that sense relative spatialinformation; gyroscopic, radio or infrared positional sensors fordetermining absolute position; and various thermal or photosensors thatrespectively detect temperature and light level changes can providesensed data values for later transmission by the tag. Intentional orunintentional modifications detected by one or more of these sensorsystems, taken in conjunction with the particular tag presented to thetag reader, can provide the basis for a powerful user interface scheme.

As those skilled in the art will appreciate, each identification numberor sensed data value that is read (sensed) by the tag can be labeled asa “senseme”, with a particular digital service or attribute beingassociated with each senseme. Although the wide variety of easilydistinguishable sensemes (e.g. identification numbers) would aloneprovide a powerful user interface to a computer, the present inventionfurther extends the flexibility of the senseme based user interface bysupporting computer control based on a multiple senseme input, withtemporally synchronous (or overlapping asynchronous) tuples of one ormore sensemes (e.g. particular identification numbers and sensed states)being read by the tag reader. Single and multiple sensemes can in turnbe extended by participation in a “sentence”. A sentence is defined as asequence of one or more temporally disjoint sensemes or senseme tuples.The sentence level allows definition of a input grammar by appropriatechoice of senseme sequence, and corollary rules governing, for example,use of active verb-like sensemes (e.g. “print”), naming noun-likesensemes (e.g. DOC1.TXT), or connectors (e.g. AND).

In effect, the present invention provides a method for transferringinformation from a tagged object with optional sensors to a tag readerconnected computer. The method comprises the steps of manipulating oneor more tags and optional tag sensors to provide a first senseme input(that includes the tag identification number) to the computer, with thefirst senseme input normally triggering a first default action by thecomputer. The tagged object may also be manipulated to provide a secondsenseme input (again including a tag identification number) to thecomputer, with the second senseme input converting the normallytriggered first default action to a second action. The first and secondsensemes (and any subsequent sensemes) together form a sentence that canbe interpreted as a command to implement a computer controlled action,whether it be to open and print a particular electronic document, unlockan electronically controlled door in response to a tag conveyed personalidentification number, display a graphical image on a computer display,or begin logging on to a computer network. In operation, for example,the sentence “establish authorization, open a file, and print the fileto printer number 3” can involve the sequential steps of reading a firsttag embedded in a picture identification card to establish useridentification, immediately presenting a second tag clipped to a paperdocument to specify a related electronic document and finally presentinga three dimensional token that appears like a small printer with anembedded third tag and pressure sensor that initiates printing of thepreviously specified document at printer number 3 after pressure sensorselectrically connected to the tag are squeezed three times. Theforegoing operation conveniently distinguishes particular electronicdocuments, and allows a user to select particular printers, (e.g. withprinter 1 requiring one sensed squeeze and printer 2 requiring twosensed squeezes) without requiring visual displays or complex inputcommands.

Utility of the foregoing system can be extended by selective shieldingof the electronic tag. Shielding can be used to arbitrarily limit thereadable range or provide strong directional reading properties for theelectronic tag, a particularly useful feature when large numbers ofelectronic tags are positioned near each other. According to the presentinvention, an electronic tag including a processor, a readable memoryfor holding an identification number connected to the processor, anantenna connected to the processor for radiofrequency broadcasting ofthe identification number, and a power supply for powering the antennato broadcast the identification number is provided with anelectromagnetic shield positioned near the antenna for reducingbroadcasting range of the antenna. The shield can, for example, bemetallic wire or sheeting positioned at least partially around or nearthe antenna, or metal lined cavities into which the electronic tag isattached. Such shields in accordance with the present invention reducereading range and can limit reading of the tag to specific directions.For example, electronic tags can be partially surrounded with shields tolimit readable electromagnetic radiation to a direction substantiallynormal to the surface of an object to which the tag is attached. Suchshields would allow large numbers of electronic tags to be closelyspaced on an object, since interfering lateral electromagnetic radiationfrom adjacent tags would be inhibited.

In certain embodiments, the electromagnetic shield is movable between afirst substantially non-blocking position and a second blocking positionthat respectively unblocks and blocks antenna broadcast. The movableelectromagnetic shield can be biased to remain in its firstsubstantially non-blocking position to allow antenna broadcast, oralternatively biased to remain in its second blocking position to blockantenna broadcast. Advantageously, a user movable shield also permitsuse of the electronic tag as a user defined communication channel fortransmitting small amounts of information. If an electronic tag having atransmitted identification number is controllably shielding anddeshielding to provide a user defined time series of readable andnon-readable intervals for the transmitted identification number, theconsequent user defined time series of readable and non-readableintervals for the transmitted identification number can be interpretedas bit-wise communication associatable with the transmittedidentification number. In effect, a user could send bit codes byintermittently interrupting reading of the electronic tag (oralternatively, by intermittently allowing reading of the electronictag). Such small amounts of user defined and transmitted information canbe used to parameterize digital services associated with the transmittedidentification number, or can even be used as personal identificationnumbers or verifiers to initiate triggering of a digital service inresponse to reading an electronic tag. For example, a tag reader can beconfigured to launch an application only after receipt of two pulses(clicks) of a particular identification number. Such a mechanism reducesinadvertent or unwanted triggering of a digital service ordinarilyprovided in response to reading an electronic tag.

In addition to selective shielding, the present invention provides forselective enablement and disablement of electronic tags. This is yetanother mechanism that eases problems associated with use of largenumbers of closely placed electronic tags, and also allows for somelimited user defined communication. An electronic tag having aprocessor, a readable memory for holding an identification numberconnected to the processor, an antenna connected to the processor forradiofrequency broadcasting of the identification number, a power supplyfor powering the antenna to broadcast the identification number, is alsoprovided with an interconnect switch for interconnecting at least twomembers selected from a set defined by the processor, readable memory,antenna, and power supply. The interconnect switch can be biased toremain normally open, preventing broadcast of the identification number,or alternatively, can be biased to remain normally closed, allowingbroadcast of the identification number.

As will be appreciated, the interconnect switch can be connected betweenthe antenna and one of the processor and the power supply, with openingor closure being controlled by a user that opens or closes electricalcontacts in the interconnect switch (using any conventional button,contact switch, electrical switch, or other conventional switch known tothose skilled in the art). In certain embodiments, a sensor can beconnected to the processor, and the interconnect switch is alternatelyopened and closed in response sensor data provided by the sensor. Forexample, an electronic tag can be equipped with an accelerometer capableof signaling when the tag is nudged or shaken. Normally, the tag remainsdisabled with its interconnect switch open. If the tag is moved, shaken,or nudged, the accelerometer senses the transient accelerations andsends a signal to the interconnect switch to close, allowing theelectronic tag to broadcast its identification number. A second shakingreverses the foregoing, causing the sensor to signal the interconnectswitch to open and break the antenna/power-supply connection (forexample), disabling the electronic tag. Sensor systems responding toheat, light, sound, force, or any suitable effect can be employed in thepresent invention.

As noted previously in connection with movable shields, user definedenablement or disablement of the electronic tags can be used for low bitrate communications directed by a user. Controllably switching aninterconnect switch of an electronic tag having a transmittableidentification number provides a user defined time series of readableand non-readable intervals for the transmitted identification number.This user defined time series of readable and non-readable interval forthe transmitted identification number can be readily interpreted asbit-wise communication associatable with the transmitted identificationnumber.

Additional functions, objects, advantages, and features of the presentinvention will become apparent from consideration of the followingdescription and drawings of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a system for identifying multipleelectronic tags and providing various digital services in response tosequential presentation of electronic tags to an electronic tag reader;

FIG. 2 is an illustration of a hand holdable computer having an attachedelectronic tag reader;

FIG. 3 is a schematic illustration showing various components of aconjoined hand holdable computer and attached electronic tag reader suchas shown in FIG. 2;

FIG. 4 is a schematic illustration of a user employing a conjoined handholdable computer and attached electronic tag reader such as shown inFIG. 2 to access an identification number of an electronic tag affixedto a two dimensional wall mounted poster, and wirelessly transfer thatinformation to a computer network for accessing related electronicdocuments;

FIG. 5 illustrates a networked printer capable of printing documentsidentified by an electronic tag, and of associating newly printeddocuments with a unique electronic tag dispensed or attached by theprinter;

FIGS. 6 and 7 taken together are a flow chart that together illustratesvarious steps in interpreting signals from electronic tags and launchingappropriate digital services;

FIG. 8 is an exemplary illustration of a movable disk shaped shieldrotatable relative to a disk having several attached electronic tags;

FIG. 9 is an example of a slidable shield;

FIGS. 10, 11, and 12 are an example of a clickable shield that can beused to send low bit rate user information by selective shielding anddeshielding of an electronic tag;

FIG. 13 is a schematic illustration of elements of an electronic tagcontrollably interconnected by an interconnect module to allow selectiveenablement or disablement of the electronic tag;

FIG. 14 is an example of a selectively enabled electronic tag, with aprocessor/memory unit normally biased to be separated from powerconverter antenna unit; and

FIG. 15 is a graph schematically illustrating a user defined bitsignaling time series of readable and non-readable intervals for atransmitted identification number from an electronic tag.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a system 10 for identifying multipleelectronic tags 32, 42, 44, and 46 (each tag generally having a uniqueelectronically readable identification number) and providing variousdigital services in response to presentation of those electronic tags toelectronic tag readers 20, 26, or 28. To access the digital services,the electronic tag reader 20 (or electronic tag reader 26 and 28) isconnected to a computer system 12, which further includes a localcomputer 14, database servers 16, and networked computers 18. In thisillustrated embodiment of the present invention, electronic tag 32 isclipped to a paper document 30, while electronic tags 42, 44, and 46 aremounted respectively on faces 52, 54, and 56 of a cube shaped polygon50. Determining what digital service is invoked is aided by varioustextual, graphical, or symbolic indicators 62, 64, and 66 respectivelylocated near each electronic tag 42, 44, and 46. The electronic tags 32or 42, 44, and 46 are brought near one or more of the tag readers,query/response signals 22 and 24 are passed between the electronic tagsand the tag reader, and the identification number of the read electronictag is passed to the computer system.

As those skilled in the art will appreciate, electronic tags can beattached permanently or temporarily to various objects, including butnot limited to the paper document 30, polygon 50, books, magazines,posters, notecards, printed advertisements, walls, floors, ceilings,furniture, electronic devices, portable computers, containers, cardboardboxes, clothing, or any other suitable object. Electronic tags can bepermanently attached by embedment in objects, adhesive attachment to anobject's surface, fixation by staples, or by mating to an object by anyother suitable attachment mechanism. Temporary fixation of electronictags to objects can be enabled through the use of object attachableclips, snaps, or ties (e.g. a paper clip with attached electronic tag, arubber band or loop of string with an attached electronic tag), simpleresting dispersal (e.g. throwing an electronic tag to rest upon afloor), insertion into a slot or receptacle, or any other suitabletemporary attachment mechanism that advantageously eases reuse of anelectronic tag by allowing successive association with various attachedobjects.

In FIG. 1, an object having more than one attached tag is indicated aspolygon 50. The polygon 50 has multiple electronic tags 42, 44, and 46,one respectively mounted on each face 52, 54, and 56. The polygon 50 canbe rotated to substantially present one face and its corresponding facecenter mounted electronic tag to the reader 20. As will be appreciated,electronic tags can be mounted anywhere on the polygon 50, including onits edges, on its vertices, in a random or semirandom distribution, orsymmetrically distributed about the polygon and centered on each face,as illustrated. As will be understood, use of such polygons (e.g. cubes,tetrahedrons, rhombic dodecahedrons, two sided planar solids, or relatedshapes), in conjunction with face centered attachment, can takeadvantage of passive shielding of the faces to limit simultaneousreadings of multiple electronic tags. Although the polygon 50 isindicated as a unitary solid object, various other shapes arecontemplated to be within the scope of the present invention. Forexample, the overall shape may be similar to various rectangular prisms,or can be spheroidal, ellipsoidal, toroidal, planar, irregular, or evenmalleable enough to allow user definition of object shape. In addition,multiple cooperating shape elements fitted with electronic tags arecontemplated, including conventional designs that permit interlocking ofmultiple shape elements, using ball and socket, a lock and key, slidableor rotatable interlocked components, chains, or any other linked object.

Electronic tags suitable for attachment to such foregoing objects inaccordance with the present invention generally broadcast a uniqueidentification number and optional data at various selectedradiofrequencies. The identification number can be user assigned atelectronic tag activation, user modifiable by software command, or fixedby an electronic tag manufacturer, depending on the particular memorysystem employed. In certain embodiments, infrared, ultrasonic, or othersuitable data transfer systems may be used alone or in combination withradiofrequency tags to transmit unique identification numbers orassociated data. The electronic tags can be inductively powered byexternal electromagnetic coils, powered by internal batteries, poweredby photovoltaic cells, powered by trickle currents from householdcurrent when available, or any other suitable power mechanism. Broadcastof the identification number and/or data can be continuous,intermittent, in response to external status inquiries, at randomintervals, or in response to local powering of the electronic tag.

The electronic tag 46 can be optionally attached to a sensor 47. Varioussensor modes can supported, including absolute or relative positionalinformation as determined by gyroscopic sensors, accelerometers, oracoustic or infrared ranging techniques. Environmental sensors,including conventional light, image, thermal, electromagnetic,vibratory, or acoustic sensors can also be present. Depending on thedesired application, environmental or positional sensors such as thoseincorporating differential GPS positioning, image analysis orrecognition, acoustic or voice identification, or differential thermalsensors can be used. Sensors may include accelerometers, compressionalor tensional strain sensors, or alternatively, embedded or attachedpositional sensors. For certain applications, continuous sensors (e.g.bilayer sheets of capacitance sensors) may be employed. One particularlyuseful continuous sensor type uses multiple capacitance or resistancestrips, with deformation pressure resulting in a positionallylocalizable analog signal proportional to the applied deformationpressure. Various sensor types can be used, including simple capacitancesensors, resistive strain sensors, analog or digital pressure switches,inductive sensors, or even fluid flow sensors. Depending on the sensortype employed, sensor data can be directly fed to the electronic tag 46in digital form, or be transformed to digital format by an generalpurpose analog/digital converter that typically provides a 4 or 8 bitrange (although as few as one or as many as 32 bits may be required byvarious applications). As will be appreciated, use of such sensorsystems provides additional input information that can form part of auser interface system enabled in part by electronic tags.

In addition to sensors, various feedback displays can be attached toelectronic tags 46. For example, electronic tag activation and operationmay be indicated by appropriate user feedback from devices positionedeither near the electronic tag 46 or near the electronic tag reader 20.For example, LED status light 49 near the electronic tag 46 and LEDstatus light 21 near the electronic tag reader 20 can be set to providean intermittent or steady visually perceptible light when the electronictag is actively transmitting to the electronic tag reader 20, providingvisual confirmation to a user of data transfer. Optionally, aconventional passive or active matrix liquid crystal display such ascommonly used in hand holdable computers, or a display based on variouselectrooptical or micromechanical techniques can be used. In addition,for certain devices a non-imaging display such as may be formed bylocalized or distributed chromatic changes in a suitable electrochromicmaterials may be used to provide visual feedback to the user.

In some embodiments of the invention, visual output may be augmented (oreven replaced) with a non-visual display. The non-visual display caninclude tactile displays based on internal actuators or auditoryfeedback. For example, one possible feedback display is based oninternal auditory speakers (emitting a range of sounds from simple“beeps” to well formed speech, depending on available processor speedand functionality) for providing user feedback. As will be appreciated,a non-visual display and its associated actuators or electronics cansupport alternative feedback modes, including, for example, forcefeedback to a user through internal actuators, tactile based feedback(e.g. with multiple surface projections for presentation of Braille orother conventional tactile user interface), modifications to the surfacetexture of the device, or any other conventional mechanism for supplyingstatus information to a user.

As will be understood, the tag reader 20 (and tag readers 26 and 28) canbe constructed to detect electromagnetic, optical, or acoustic signalsat various frequencies. In certain embodiments, the tag reader 20 canwrite as well as read electronic tag identification numbers and data. Itwill be understood that the particular digital service invoked inresponse to reading a tag can depend on which tag reader 20, 26, or 28reads the tag, the order in which electronic tags are read by one ormore of the electronic tag reader, the duration of presentation of anelectronic tag to a particular reader, or any other suitable userunderstandable electronic tag reading protocol.

After an electronic tag is read, the computer system 12 is used tointerpret the identification number of the electronic tag and providethe requested digital service. Semantic binding of the identificationnumber can be provided by a computer 14 (which can be a desktopcomputer, a dedicated electronic tag processor, or a hand holdable pencomputer), by networked connected database servers 16, or by otheraccessible networked computers 18. Computers in computer system 12 canbe interconnected by various hard wired or wireless connections, and maysupport various communication protocols and designs, including use of aserial tethered (using, for example the RS-232C interface protocols),use of infrared signals adhering to widely utilized IRDA communicationstandards, or use of radiofrequency signals (which can be, for example,a cellular telephone, 900 MHz radio, or digital PCS telephoniccommunications). Alternative communication standards, or evenalternative communication carriers such as those based on optical oracoustic techniques, can of course be employed. Other possiblecommunication targets for computer system 12 include automation controlsystems, security authorization units, wireless personal digitalassistants, notebook computers, or any other suitably equippedelectronic system.

Binding digital services to particular electronic tags can be userdefined, provided as default bindings by a system provider, learned bythe system through repetition or context, or some combination of theseand other suitable semantic binding techniques. For example, a databaseformat can be constructed in which each identification number of anelectronic tag is a database key. Associated with that key is a set ofdigital actions to undertake when that identification number of anelectronic tag is detected. There is an enumerated list of suchactions—display a Web page, display a text document, display a date in acalendar, go to a certain location in a document, and so forth. Eachaction is parameterized by a list of (name, value) pairs appropriate forthat action. For example, the action to display a text document haspairs associated with it indicating the file to display, whether itshould display in read-only mode, or whether the file should beconverted to a particular format. By using this general (name, value)mechanism, and having the database be in human-readable ASCII form, auser can easily add new tags and new types of actions to an initiallyprovided list. Since the database is editable, associations betweenidentification numbers of electronic tags and digital services can bemodified at any time by a user.

In addition to reading a single electronic tag and its uniqueidentification number, the user interface of the present invention canbe extended by sequentially or simultaneously reading multipleelectronic tags from one or more tag readers. As those skilled in theart will appreciate, each identification number or sensed data valuethat is read (sensed) by the tag can be labeled as a “senseme”, with aparticular digital service or attribute being associated with eachsenseme. Although the wide variety of easily distinguishable sensemes(e.g. identification numbers) would alone provide a powerful userinterface to a computer, the present invention further extends theflexibility of the senseme based user interface by supporting computercontrol based on a multiple senseme input, with temporally synchronous(or overlapping asynchronous) tuples of one or more sensemes (e.g.particular identification numbers and sensed states) being read by thetag reader. Single and multiple sensemes can in turn be extended byparticipation in a “sentence”. A sentence is defined as a sequence ofone or more temporally disjoint sensemes or senseme tuples. The sentencelevel allows definition of a input grammar by appropriate choice ofsenseme sequence, and corollary rules governing, for example, use ofactive verb-like sensemes or naming noun-like sensemes. For example, theverb “print” is associated with tag 42, the textual lettering “PRINT”and the symbolic icon of a printer 62 on the polygon 50, while the noun“http://www.test.com/DOC1.TXT”, is associated with a URL to anelectronic copy of a document corresponding to the printed document 30.Just as in English, context can affect how sensemes are interpreted. Forexample, a small model of a printer with a tag on it can produce asenseme interpretable as either the verb “print” or the noun “printer”depending on its surrounding sensemes.

In effect, sensemes taken together form a sentence that can beinterpreted as a command to implement a computer controlled action (i.e.digital service), whether it be to open and print a particularelectronic document, unlock an electronically controlled door inresponse to a tag conveyed personal identification number, display agraphical image on a computer display, or begin logging on to a computernetwork. In operation in the system of FIG. 1, for example, the sentence“establish authorization, open a file, and print the file to printernumber 3” can involve the sequential steps of reading a electronic tag46 to establish user identification, immediately presenting anelectronic tag 32 clipped to a paper document 30 to specify a relatedelectronic document (i.e. “http://www.test.com/DOC1.TXT”) and finallypresenting electronic tag 42 (positioned next to the small printersymbol) just after squeezing pressure sensor 45 three times (note thatsensor 45 is electrically connected to electronic tag 42 to pass smallamounts of pressure response data) to initiate printing of thepreviously specified document at printer number “3”. The foregoingoperation conveniently distinguishes particular electronic documents,and allows a user to select particular printers, (i.e. with printer 1requiring one sensed squeeze and printer 2 requiring two sensedsqueezes) without requiring visual displays or complex input commands.

As will be appreciated by those skilled in the art, some temporallydistinguishable sensemes (or combinations of sensemes) further representsensemes used as a basis for a grammar in accordance with the presentinvention. All of the following described sensemes can be modified bynumerous variations in identity of electronic tag (e.g. tag number237654 vs. 124934), class of electronic tag (e.g. the 1000 series versusthe 4000 series), presentation of sequence of particular electronictags, repetition or timing variations in tag presentation or sequencing,as well as sensor input such as positional information, appliedpressure, force utilized in squeezing a pressure sensor. In addition,timing of various objects (whether quick, slow, or alternately quick andslow) can modify interpretation of a senseme. For example, if “squeeze”is taken as a typical senseme supplied by a pressure sensor 45, one canappreciate various squeeze operations such as quick squeeze, slowsqueeze, hard squeeze, soft squeeze, narrow squeeze, or wide squeeze.For purposes of the present invention, all such squeeze sensemes wouldbe considered members of the “squeeze” class, with individual variationsacting as possible modifiers to electronic tag identification number andits default semantic binding.

To better understand operation of a particular embodiment of the presentinvention, FIG. 2 is an illustration of a tag reading system 100 forreading an electronic tag 150 with optional connected sensor 160. Thesystem 100 includes a hand holdable pen computer 110 with input/outputaided by pen 112 and touch sensitive display surface 114, wirelessinfrared or radiofrequency port 140 for communication with a network(not shown), and an attached electronic tag reader 120. The tag reader120 is powered by line 132 to pen computer 110, and serialcommunications with pen 110 are maintained by serial connection 130(e.g. an RS-232C connection).

FIG. 3 is a schematic illustration of the tag reading system 100 of FIG.2. As seen in FIG. 3, the electronic tag 150 includes memory 152 forholding an identification number, other user or system defined data, andoptionally any sensor data from sensor 160. A processor 154 connected tothe memory 152 handles onboard logic, including optional datapreprocessing, power control, and transmission/reception tasks. It willbe understood that the processor 154 may include only a few logicalelements, or can be a full featured microprocessor with memory 152 onthe microprocessor chip. A power supply 156 (e.g. a battery, aninductive power converter, photovoltaic cells, etc.) is used to powerthe tag 150, and data transmissions are broadcast by antenna 158. Thetag reader 120 includes tag-reader-processor/memory-buffer 120, andelectromagnetic reading coil 122.

Implementation of an electronic tag reading system similar to thatillustrated in conjunction with FIGS. 2 and 3 is possible usingcommercially available tags from Trovan, Ltd., having a website at<www.trovan.com> (hereinafter “Trovan”) and tag readers suitablymodified by connection of the tag reader to a hand holdable computer. ATrovan tag consists of a small coil and a tiny microchip connected tothe coil, collapsing the memory 152 and processor 154 into a singlelogic module, and collapsing the antenna 158 and power supply 156 into asingle coil that inductively powers the tag and broadcasts tagidentification information. A Trovan tag has no associated optionalsensor 160, and there is no on tag battery, with power being transferredto the tag from the reader 120 at each interrogation cycle. Typically areader 120 will initiate an interrogation cycle by generating a fieldalternating at a frequency of 128 kHz. If it is close enough to a tag,the changing field will induce a current in the coil contained in thetag. This current can be rectified and used to charge a capacitor thatafter sufficient time will have enough stored charge to power itsattached integrated circuit. When this condition is met, the chip willactivate an oscillator at half the interrogation frequency and thissignal is fed back into to the tag coil. The tag reader 120 is designedas a full duplex system—it can receive and transmit concurrently. Thereaders sensitive receiver is tuned to exactly half of the interrogationfrequency and is listening for a phase-modulated signal from the tag at64 kHz. During this process the tag will modulate the response signalwith a data frame containing 64 bits of information. Each frame willcontain an organization or client code, a unique ID code and a checksum.For each client, 2³⁹ tagging codes are available (approx. 550 billion).

Various sized Trovan tags can be used in the present invention. Largertags contain a larger coil, but have similar electronics to the smallerversions. Larger tags have a greater read range. The tradeoff betweentag size, reader coil size, and read range is governed by theapplication. The following reader and tags have been tested in system100: LID 656 tag reader; ID 100A -cylinder tag (2.2×11.5 mm); ID200—round tag (25.5 mm(dia),4.5 mm (thick)); ID 300—round tag (25mm(dia), 4.8 mm (thick)); and ID 400—credit card size and shape. Readingdistance typically ranges from contact to as much as 12 centimeters whenan electronic tag is unshielded and fully enabled.

The tag reader 120 is designed as an embedded system that includes asimple embedded processor 124 whose task is to identify the receivedsignal and then buffer a digital representation of it in memory. A tagreader will typically support a simple serial RS232 interface to allow aconnection to be made with a general-purpose computer such as a laptopor PDA. When it has read a valid tag, a simple audible alert or flashingan LED can also be used to give a simple audio or visual indication ofthe tag reading process. For ease of use, a tag reader 120 can beattached to a hand holdable computer. For example, a Fujitsu 1200, (atablet computer with a 20 cm diagonal and VGA resolution) can be matedto a Trovan 656 OEM reader. Such a tag reader can be easily concealed onthe back of the tablet with power delivered by tapping into the internalpower supply of the machine (line 132), with only minor modifications tothe computer's housing. All of the interpretation and storage of thetag-IDs is carried out by a custom developed software system, with theTrovan reader acting to provide valid digital identification numbers ofthe tags across the serial interface.

The reader and the RF-tags communicate by inductive coupling between twocoils. The reader coil is large relative to the tag and is responsiblefor providing energy to it and for reading the small radio-signal thatis returned. Placement of the reading coil on the housing of a tabletcomputer has to be done bearing two issues in mind. First, the readingcoil must be in a position that is both convenient and natural for auser interacting with tagged objects. Second, the mounting location mustbe chosen to minimize interference from the host computer. Suitableshielding needs to be in place to ensure a coil is given the bestpossible chance at reading a tag, without interfering with the pencommunications. If care is not given to this part of the design, theapparent tag reading range of the system 100 can be reduced to acentimeter or less. The Trovan system can only read one tag at a timeand it is important to physically control the number of tags that are inthe proximity of the read coil. If two tags are readable, the tagresponses will interfere and no data will be read. However, it has beenfound that if two tags are present but one is at least 5 mm closer tothe center of the read coil, then the nearer tag will still be readsuccessfully. Some care needs to be taken with a design that uses aminimal tag separation, as it may be hard for a user to accuratelyselect the desired region absent tag shielding or selective disablementof tags. Also some inter-tag interference may be data dependent and maybe affected by the ID of each tag.

Because positioning of the read coil is critical to the ease of use ofthe system 100, this problem has been examined in some detail. The exactdimensions of the read coil affects the overall inductance and the 0value. Dimensions that are optimal for one application are often notoptimal for another. For example, placing a reading coil on theunderside of a tablet computer, where there is lots of space to embedit, gives a designer more flexibility with the coil geometry than if itwere on the front, where space is limited. To solve this problem avariety of coils could be positioned around the computer housing. Themodifications allowed a user to chose between sensing locales with amanual switch, or allow for automatic coil switching. Users can switchbetween sensing locales electronically by sending commands through theserial port. In some cases it might be desirable to use the physicalworld to automatically choose the active coil. For instance, if thetablet was placed on a table, a micro-switch could detect the contactpressure and thus disable the coil at the back of the unit and switch ina more useful coil at the front. An alternative approach is tosequentially multiplex the various coils onto the reading electronics.This solution has the advantage that our tablet computer will be readingfrom the correct coil once in each multiplexing cycle. In certainembodiments of the present invention, the reading range of the coil canbe selectively reduced or enhanced. This can be accomplished byadjustments to coil electronics, selection of different coils, use ofcoil shields, and selective introduction of materials that modify coilproperties such as its inductance or configuration. This can be usefulwhen operating in environments with large numbers of electronic tags,where desired reading range may be reduced, or in environments with fewtags, where desired reading range may be expanded.

Network access is provided by wireless port 140 to support virtualassociations (semantic bindings) which refer to external documentsand/or digital services. To provide this network connection for thesemobile devices, a Proxim Rangelan 2 frequency-hop spread-spectrum radiois used. A portable computer that has a free PCMCIA slot can be readilyfitted with a PC-card version of the Proxim radio. This type of radiosystem operates at 2.4 GHz. The particular units used in system 100 aredesigned to provide up to 500 feet of coverage centered on each networkaccess point. The raw bandwidth of the radio is 1.6 Mbps with a datarate of 500 kbps available to applications, taking into account theprotocol overhead. An access point serves as a bridge between mobiledevices equipped with a radio and an existing wired network. With only asmall number of access points wireless connectivity can be providedthroughout a building. In operation, use of a radio network allows mostdocuments stored on a local file server to be viewed within a fewseconds.

The software infrastructure to support this functionality includes asingle thread of a multi-threaded Windows program, and can be easilywritten by one skilled in the art. The program, written in C++, monitorsthe serial port for incoming tag identification numbers. A second threadis notified of each incoming tag and displays the appropriateapplication and document. Some application programs are invoked asremote “black box” services via “spawn”-type commands (e.g. NetscapeNavigator, audio players), while others are communicated with at adeeper and finer level via OLE (e.g., Word, Internet Explorer, Outlook).In effect, the software layer reads the incoming tag identificationnumbers, examines the associated tag file, which contains the mapping ofidentification numbers to actions, and then executes the desired commandsequences to invoke selected digital services. Sometimes the same tagwill be rapidly detected twice: to filter this out, a hysteresis isimposed on each tag event. If a tag identification number is detectedwhich is not associated with any semantics, the program can eitherignore the tag, or launch a dialog box querying the user for thesemantics of the tag. The latter mechanism is used to update our systemwhenever a tag is attached to a new document. Ordinarily a sharednetwork database (such as discussed in connection with FIG. 1) is usedto map digital services to each tag identification number.

FIG. 4 is a schematic illustration of a tag reading system 200 thatallows a user employing a conjoined hand holdable computer 110 andattached electronic tag reader such as shown in FIG. 2 to accessidentification numbers of electronic tags affixed to a two dimensionalwall mounted poster 232 or some other suitable tag enabled object. Thecomputer 110 can wirelessly transfer that information to a transceiver220 connected to a computer network 230 for accessing electronicdocuments or invoke digital services semantically bound to electronictags. Documents can be found at a database server 222, a local desktopcomputer 224, and can be printed at a network computer 226. In typicaloperation, a user would read one of the tags on the poster, transferringan identification number to the database server 222 on the network 230.The semantic binding between the identification number and the digitalservice is made, and, for example, a document can be printed at printer226 or an electronic document retrieved from desktop computer 224.

For best results, the electronic tags attached to the poster 232 areseparated to ensure non-overlapping read zones. For example, electronictags 240, 242, 244, and 246 (each associated with text or symbolicindicia on poster 232) have respective non-overlapping read zones 250,252, 254, and 256 within the dotted lines. If tags need to be set veryclose, shielded tags 260, 262, and 264 with electromagnetic shieldsprovided to substantially reduce lateral detection range can be used.Alternatively, a selectively disabled tag 266 that is not powered or isotherwise disabled until manually or automatically enabled, can be usedto allow for close packing of large numbers of tags without adverse datareading impact.

In yet another embodiment of the present invention, FIG. 5 illustrates anetworked printer 326 capable of printing documents identified by anelectronic tag 332 clipped to a paper document 330. In addition, theprinter 326 can associate newly printed documents 346 with a uniqueelectronic tag 342 dispensed by dispenser 344 or attached by tag module340 of the printer 326. Associations to the electronic tags can be madevia network machines 18 contacted through network 230, using a mechanismsuch as previously discussed in connection with the foregoing Figures.Operation of the network printer can be controlled be provision ofmultiple tag readers 320, 322, and 324, each reader being attached to aparticular printer operation. For example, if a user brings tag 332 tobe read by tag reader 320, a color copy of the document to which the tag332 is clipped can be generated. Reading the tag 332 from reader 322generates a black and white copy, while reading the tag from reader 324transfers an electronic copy of the document to a particular networkmachine for storage, modification, or printing. As will be appreciated,the tag 332 can be attached to a portable, hand holdable computer suchas discussed in connection FIG. 2. If the tag 332 is brought near theprinter 326, the printer 326 determines which computer is associatedwith that tag and queries the computer (by wireless connection) todetermine identity of a document currently displayed on the computerscreen (if any). If so, this document can be retrieved, and then beoptionally printed or otherwise modified depending on user selectedoptions.

To better understand operation of one particular embodiment of thepresent invention, FIGS. 6 and 7 together provide a flow chart showingsoftware logic flow as applied to a particular usage scenario. Forexample, consider a usage scenario in which a user has a pen computeraugmented with a tag reader. In this scenario, the user will bring threetags to the attention of the reader. The first tag, located on the backof the user's corporate ID, tells the pen computer to “log in” the userand load his associated profile. The second tag, located on a binderclip on a document, tells the pen computer to display the latestelectronic version of the document on its display. The third tag,located on a surface of a network printer, tells the pen computer toprint the current document to the printer—the user raps the pen computeron the printer twice in quick succession, indicating a desire to printtwo copies. The sequence of events is as follows:

When the user brings their corporate ID with associated tag #1 withindetection range of the tag reader, a first electronic signal 351 iscreated within the reader. This signal is then converted into digitalform in step 352, e.g. an ASCII string containing the data “ID#1” (orsome similar disambiguating string). This data string is thentransmitted from the reader to the interpreting computer in step 353.Assuming the interpreting computer is interrupt-driven (step 354 is a“yes”), a thread of a monitoring program on the computer is waiting forthis data in step 355. The thread is activated in step 357, it receivesthe data string “ID#1”. The processor associates a time stamp with thisevent in step 358, and continues on to further processing. In step 359,the processor checks to ensure that this isn't a repeat of the sameevent, i.e. that the users bringing of the ID card to the reader hasn'ttriggered multiple events. If so, the event is ignored. If not (step 359says “NO”), processing continues. The processor consults a networkdatabase to find out what it should do when it senses this tag in step361. In this example, the tag is already in the database (step 362 says“YES”), and so a command string indicating semantics associated with thetag is loaded into the computer, interpreted, and executed (step 364).For example, in this case, the profile associated with the user(preferred screen size, preferred font size, network passwords, etc.) isloaded into the computer, step 368.

A few seconds later, the user brings a binder clip augmented with a tagclose to the tag reader and a second electronic signal 351 is createdwithin the reader. This signal is then converted into digital form instep 352, e.g. an ASCII string containing the data “ID#2” (or somesimilar disambiguating string). This data string is then transmittedfrom the reader to the interpreting computer in step 353. Steps 354,355, 357, 358, and 359 are performed analogously to the first tag. Instep 361, the network database is consulted, with a key of “ID#2”. Inthis example, the tag is already in the database (step 362 says “YES”),and so a command string indicating semantics associated with the tag isloaded into the computer, interpreted, and executed (step 364). In thiscase, step 366 is executed, a document-display application (such asMicrosoft Word) is launched, and told to display the given document.

The user now brings the tag reader within range of a tag located on anetwork printer. a third signal 351 is created within the reader. Thissignal is then converted into digital form in step 352, e.g. an ASCIIstring containing the data “ID#3”. This data string is then transmittedfrom the reader to the interpreting computer in step 353. Steps 354,355, 357, 358, and 359 are performed analogously to the first tag. Instep 361, the network database is consulted, with a key of “ID#3”. Inthis example, the tag is already in the database (step 362 says “YES”),and so a command string indicating semantics associated with the tag isloaded into the computer, interpreted, and executed (step 364). In thiscase, step 368 is executed: the computer stores the name of the networkprinter, but does not yet print, since it needs to wait and see how manycopies it should print.

A short time later the user again brings the tag reader within range ofthe network printer tag, a fourth electronic signal 351 is createdwithin the reader. Steps 352, 353, 354, 355, 357, 358, 359, 361, and 362are performed analogously with the third signal. In step 364, theprocessor determines that this is the second time in a short time periodthat it has seen this same tag, and so step 368 is executed: thecomputer associates “2” with the number of copies to print. Finally,when a specified amount of time has passed without any more data beingreceived in serial port 357, the processor prints the document at theassociated printer with the associated number of copies.

Simple modifications or augmentations of electronic tags in accordancewith the present invention can enhance ease of employing multipleelectronic tags in various usage scenarios. For example, FIG. 8 is anexemplary illustration of multi-tag shielding system 400 that includes amovable disk shaped shield 420 rotatable (as indicated by arrow 422)about an attachment point 412 relative to a base disk 410. The base disk410 has multiple attached electronic tags 416 configured to radiateelectromagnetic, optical (including infrared), acoustic, or other signalthat is blockable or substantially reduced in signal strength by theshield 420. The shield 420 is defined to have an aperture 421 sized toexpose only a single tag 416 as the shield is rotated. In operation, auser can read a number or other symbolic or textual indicia 414 printednear each tag 416 as the shield 420 is rotated. When the proper numberor indicia is revealed through the aperture 421, the electronic tag iscapable of radiating a signal readable by a suitable tag reader (notshown). By sequentially “dialing” a series of numbers, and presentingeach number and associated tag to the tag reader (e.g. to read thenumber 3-5-6), a user can employ the system 400 as a low cost personalidentification number that authorizes invocation of digital serviceswhile preventing unauthorized possessors of the disk from accessingvarious digital services. Alternatively, each tag can be associated witha particular digital service such as printing, file transfer,authorization, or identification, or any other semantic binding desiredby the user.

FIG. 9 is yet another example of a multi-tag shield system 430 havingslidable shield 434 movable (as indicated by arrow 436) relative to abase 432. The base 432 has two attached electronic tags 442 and 440configured to radiate electromagnetic, optical (including infrared),acoustic, or other signal that is blockable, redirectable, orsubstantially reduced in signal strength by the shield 434. As will beappreciated by those skilled in the art, in addition to simple tagnumber identification, low bit rate user information can be imparted toa tag reader and associated computer system (such as discussed inconnection with FIG. 1) by presenting a selected tag 440 or 442 forcertain durations, or in certain user defined sequences. Presentation isaccomplished by selectively sliding the shield 434 between a suitableposition alternately blocking tag 440 and tag 442. Although only smallamounts of information can be transmitted by this or similar methods, itcan be a useful mechanism for parameterizing digital services associatedwith a tag, providing an equivalent of a personal identification number,or otherwise modifying tag associated digital services.

To simplify transmission of information, a mechanism 450 thatfacilitates user defined on-off tag reading can be employed. Asillustrated in FIGS. 10, 11, and 12, a flexible shield 454 defining anaperture 456 is attached at one end to a base 452 having a partiallyembedded electronic tag 458. As seen in top and side view respectivelyin FIGS. 10 and 11, the shield 454 is normally biased to preventradiation from tag 458 of electromagnetic, optical (including infrared),acoustic, or other signal detectable by an external tag reader such asdiscussed in connection with FIG. 1. However, as shown in FIG. 12, auser can depress the shield 454 toward the base 452 in the directionindicated by arrow 460, causing the aperture 456 to move transientlyinto position over the radiating tag 452. This transient position allowsradiation of a detectable signal 462 with a signal amplitude andduration measurable by tag reader and associated computer system. Using,for example, techniques such as those based on Morse code to conveybitwise information by user controlled interruptions of a continuouslyradiating signal 462, mechanism 450 can used to send low bit rate userinformation by selective deshielding and shielding (by downwardlyclicking and releasing). Such user information can be employed asdiscussed in connection with FIGS. 8 and 9 above.

Still another method of easing problems associated with multipleelectronic tags (and also allowing user transmission of small amounts ofinformation based on interruption to electronic tag signals) isdiscussed in connection with FIG. 13. This Figure schematicallyillustrates a selectively enabled electronic tag 540 having memory 552,processor 554, power supply 556, and signal radiator 558 (typically anantenna or light emitting diode). An optional sensor module 560 forproviding sensed data to the processor can also be connected. Theseelements are controllably interconnected by an interconnect module 562to allow selective enablement or disablement of the electronic tag 540.The interconnect module 562 can be activated or deactivated by a useremploying a electromechanical controller 561 (such as a switch, button,relay, or other suitable mechanism). The interconnect module 562 canalso be activated or deactivated by a user employing a softwarecontroller 561. The software controller 561 (which can be usercontrolled or under automatic control) can also be used to directlydisable or enable the processor 554.

FIG. 14 is an example of a selectively enabled electronic tag 550constructed at least partially in accordance with the schematic of FIG.13. The electronic tag has four mechanical elements, including casing570, a movable piece 574 held in the casing, a movable piece 576 alsoheld in the casing, and a spring 572 connecting the movable piece 574and the movable piece 576 to each other and the casing 570, with thespring 572 biased to oppose user exerted forces 577 and 575 that wouldtend to bring the mobile pieces together. The movable piece 574 is alsoconfigured to support a power supply 556 and antenna 558 forelectromagnetic signal radiation. The movable piece 575 is similarlyconfigured to support memory 552 for holding tag identification numberand sensor data, a processor 554, and a sensor 560. The movable piece574 also supports an electrical contact 592 capable of electricallycontacting a similar electrical contact 590 mounted on movable piece590. In operation, a user can enable the normally non-radiating tag bypinching together the movable pieces 574 and 575 so that the contacts590 and 592 are brought into electrical contact. This completes acircuit that immediately causes radiation of the tag identificationnumber. As will be appreciated, bitwise information transmission by usercontrolled interruptions of the radiating signal are contemplated to bewithin the scope of the invention.

To better illustrate signaling methods in accordance with the presentinvention, FIG. 15 is a simplified graph 600 schematically illustratinga user defined bit signaling time series along an intensity axis 610 andtime axis 612 of a potentially readable interval 620 for a transmittedidentification number from an electronic tag. This graph 600 illustratesresponse of a radiating tag that regularly supplies its identificationnumber (pulses 630 at intervals 632 and 636) when fully enabled and notshielded. When the tag is disabled or shielded, no signal is received,as illustrated by interval 634 and 638. For purposes of the presentinvention, intervals 632 and 636 can be interpreted as having values of“1”, while intervals 634 and 638 have a value of 0. As will beunderstood, this series can be read as a binary “1010” over the relevantsignaling time period 620. Using such techniques, a user can easilytransmit small amounts of information to a suitable computer system.

As those skilled in the art will appreciate, other variousmodifications, extensions, and changes to the foregoing disclosedembodiments of the present invention are contemplated to be within thescope and spirit of the invention as defined in the following claims.

The claimed invention is:
 1. A system for identifying multipleelectronic tags, the system comprising: a plurality of electronic tagsattachable to a single object, each electronic tag having anon-overlapping readable region, and each electronic tag having a uniqueidentifier; an electronic tag reader configured to read the uniqueidentifier of each electronic tag within the non-overlapping readableregion; at least one shielding member provided on each electronic tag,the at least one shielding member at least one of: selectively limitinga readable range of the corresponding electronic tag by the electronictag reader, and selectively providing strong directional readingproperties for the corresponding electronic tag; and a computing systemconnected to the electronic tag reader to provide digital services inresponse to reading the unique identifier of each electronic tag.
 2. Thesystem of claim 1, wherein the single object is three dimensional. 3.The system of claim 2, wherein the three dimensional single object has aplurality of faces, with at least some of the faces having an attachedelectronic tag.
 4. The system of claim 3, wherein the single threedimensional object with a plurality of faces is a polygon, with at leastsome of the faces having an attached electronic tag.
 5. The system ofclaim 1, wherein the single object presents a planar surface, withattached electronic tags positioned with respect to each other on theplanar surface at distances sufficient to ensure a non-overlappingreadable region for the electronic tag reader.
 6. The system of claim 1,further comprising an antenna connected to the electronic tag reader,the antenna capable of transmitting a signal to the electronic tags,wherein the at least one shielding member is movable between a firstsubstantially non-blocking position and a second substantially blockingposition that respectively unblocks and blocks communication with theantenna.
 7. A system for identifying electronic tags, the systemcomprising: an electronic tag reader configured to read uniqueidentifiers of electronic tags; at least one shielding member providedon each electronic tag, the at least one shielding member at least oneof: selectively limiting a readable range of the correspondingelectronic tag by the electronic tag reader, and selectively providingstrong directional reading properties for the corresponding electronictag; and a portable computer physically and electrically attached to theelectronic tag reader, with digital services provided in response toreading the unique identifier electronic tags.
 8. The system of claim 7,wherein the portable computer further supports a wireless networktransceiver for communication with a computer network.
 9. The system ofclaim 7, further comprising an antenna connected to the electronic tagreader, the antenna capable of broadcasting a signal to the electronictags, wherein the at least one shielding member is movable between afirst substantially non-blocking position and a second substantiallyblocking position that respectively unblocks and blocks communicationwith the antenna.
 10. A system for associating an electronic tag and adigital service, the system comprising: an electronic tag attachable toan object, with the electronic tag having a unique identifier forinvoking a digital service; at least one shielding member provided onthe electronic tag, the at least one shielding member at least one of:selectively limiting a readable range of the electronic tag; andselectively providing strong directional reading properties for theelectronic tag; and symbolic indicia located on the object in proximityto the electronic tag, with the symbolic indicia configured to representthe digital service invoked in response to reading the electronic tag.11. The system of claim 10, wherein the symbolic indicia is a graphic.12. The system of claim 10, wherein the symbolic indicia is text.
 13. Anelectronic tap comprising: a processor; a sensor, connected to theprocessor, the processor receiving sensor data from the sensor; at leastone shielding member provided on the electronic tag, the at least oneshielding member at least one of: selectively limiting a readable rangeof the electronic tag and selectively providing strong directionalreading properties for the electronic tag; and readable memory thatholds an identification number the readable memory connected to theprocessor; writable and readable memory, the writable and readablememory connected to the processor; an antenna, connected to theprocessor, the identification number and the sensor data transmittableby the antenna; and an inductive power converter that powers the antennato transmit the identification number and the sensor data in response toexternally applied transient electromagnetic power.
 14. A method fortagging an object with multiple electronic tag, the method comprising:providing a plurality of electronic tags having unique identificationnumbers and defined reading zones; providing at least one shieldingmember on each electronic tag, the at least one shielding member atleast one of: selectively limiting a readable range of the correspondingelectronic tag reader, and selectively providing strong directionalreading properties for the corresponding electronic tag; and attachingthe plurality of electronic tags to the object at a distance from eachother sufficient to ensure non-overlapping reading zones.
 15. The methodof claim 14, further comprising moving the at least one shielding memberbetween a first substantially non-blocking position and a secondsubstantially blocking position.